CHEMISTRY OF A HEWS EGG. 21 



four eggs were laid, the shells of which weighed 

 nearly 409 grains ; of this amount 276 grains were 

 carbonate of lime, Yl\ phosphate of lime, and 10 

 gluten. But there is only a little carbonate of lime 

 in oats, and from whence could these 409 grains 

 of the rocky material have been derived'? The 

 answer to this question opens up some of the most 

 curious and wonderful facts connected with animal 

 chemistry, and affords glimpses of many of the 

 operations of organic life, which, to the common 

 mind, seem in the highest degree paradoxical and 

 perplexing. The body of a bird, like that of a 

 man, is but a piece of chemical apparatus, 'made 

 capable of transforming hard and fixed substances 

 into others of a very unlike nature. In oats there is 

 contained phosphate of lime, with an abundance of 

 silica, and the stomach and assimilating organs of 

 the birds are made capable of decomposing or rend- 

 ing asunder the lime salt, and forming with the 

 silica a silicate of lime. This new body is itself 

 made to undergo decomposition, and the base is 

 combined with carbonic acid, forming carbonate of 

 lime. The carbonic acid is probably derived from 

 the atmosphere, pr more directly perhaps from the 

 bloodv These chemical changes among hard in- 

 organic bodies are certainly wonderful when we 

 reflect that they are brought about in the delicate 

 organs of a comparatively feeble bird, under the 



